1. Field of the Invention
The invention relates to closure, in particular for a nutrient medium container, wherein a lower part can be covered by an upper part, wherein the lower part and the upper part can be locked against each other by means of at least one locking receptacle and at least one locking part by rotating the lower part and the upper part about a longitudinal axis, and wherein the locking receptacle has a receptacle groove that is covered by a shoulder and that extends perpendicularly to the longitudinal axis, in which receptacle groove the locking part engages.
2. Description of the Related Art
A closure for a nutrient medium container, wherein a lower part can be covered by an upper part, is known from DE 10 2007 027 273 A1. The lower part and the upper part can be locked against each other through two or more locking receptacles and two or more locking parts by rotating them about a longitudinal axis. To do so, the locking receptacle has a receptacle groove that is covered by a shoulder and that extends perpendicularly to the longitudinal axis, in which receptacle groove the locking part engages.
The disadvantage of this is that when used in automatic systems in which the upper part is automatically positioned on and/or removed from the lower part, for instance by a robot arm, an undesirable error rate occurs due to incorrect positioning when the locking part comes in contact with the shoulders of the locking receptacle during positioning.
The same disadvantages occur with regard to the closures known from US 2006/0240549 A1, U.S. Pat. No. 6,969,606 B2 and U.S. Pat. No. 6,969,607 B2. These documents also disclose nutrient medium containers or “petri dishes” in which a lower part has a locking receptacle with a shoulder oriented perpendicularly to the longitudinal and/or rotational axis, which shoulder covers a locking part of an upper part and/or lid when in the locked state.
These known closures also lead to undesirable positioning problems in automatic systems.
The task of the present invention is therefore to design the known closures and/or locking systems, especially for nutrient medium containers, such that the frequency of incorrect positioning is reduced or eliminated entirely when the upper part is automatically positioned on the lower part.